issues with 1988 tess

This is a "normal" failure for either a US TR (F113A040 engine) or a late euro TR (F113B engine) -- please indicate what version TR you have.

What happens is:

Mode 1 = when the starter motor is cranking, a +12V signal is fed directly to the tachometric relay, which closes it, and a closed tachometric relay closes the fuel pump relays.

When you release the key to the "run" position:

Mode 2 = the signal from the 7/12 coil primary goes to the tachometric relay, and this also closes the tachometric relay so the fuel pump relays should stay energized.

Mode 1 is working (since your TR starts), but something is not working for Mode 2 (it runs for a few seconds until the fuel pressure drops). The problem could be -- bad 7/12 ignition, bad tachometric relay, bad wiring to tachometeric relay, etc.. First thing to do is confirm/deny if you have spark occurring on the 7/12 bank during cranking and for the few seconds it runs -- if not, you need to fix that; if you do have spark on the 7/12 bank, but it still dies, then you need to look at the input and output signals from the tachometric relay -- see this thread for that:

http://ferrarichat.com/forum/showthread.php?t=97603&highlight=tachometric+relay+terminal+15&page=2

give a shout if any questions come up (but please post what you find/fix too).

 

Interesting steve.

This os obviously completely different than the 512TRS. Great explanation!

 

Dear Ferraristi,

....and don't forget:

Check the ignition module on bank 7/12. It receives the tachometric signal to fire the engine. So if your tachometric relay is fine, but no engine start, switch the modules on top of the coils. If you only have the 1 bank now firing, you have a bad module.

Oh it sounds sooooo easy now....guess how long and how much tracing ( with Steve M's help ) to find it was a bad coil module.


Shamile

Freeze...Miami Vice !